Read Range Enhancement of a Sensing RFID Tag by Photovoltaic Panel

Abstract

An RFID tag with energy harvesting and sensing capabilities is presented in this paper. This RFID tag is based on an integrated circuit (SL900A) that incorporates a sensor front-end interface capable of measuring voltages, currents, resistances, and capacitances. The aim of this work is to improve the communication distance from the reader to the tag using energy harvesting techniques. Once the energy source and harvester are chosen according to the environment of work, the conditioning circuit for energy management has to be appropriately designed with respect to the nature of the transductor. As a proof of concept, a photovoltaic panel is used in this work to collect the energy from the environment that is managed by a DC-DC converter and stored in a capacitor acting as battery. Such energy is used to support the power system of the tag, giving autonomy to the device and allowing data logging. In particular, the developed tag monitors the ambient temperature and the power voltage. It would be possible to add external sensors without changing the architecture. An increase in the read range of more than 200% is demonstrated. This feature is especially interesting in environments where the access could be difficul